public class Answer3 {
    // 大数乘法
    //https://www.nowcoder.com/practice/c4c488d4d40d4c4e9824c3650f7d5571?tpId=196&tqId=37177&ru=/exam/oj

    public static void main(String[] args) {
        String ss="733064366";
        String tt="459309139";
        System.out.println(solve(ss, tt));
    }

    public static String solve (String s, String t) {
        char[] ch1 = s.toCharArray();
        char[] ch2 = t.toCharArray();
        StringBuilder st = new StringBuilder();
        long y = 0;
        for (int i = 0; i < ch2.length; i ++) {
            y += Math.pow(10, ch2.length-1 -i) * (ch2[i] - '0');
        }
        long sum = 0;
        for (int i = ch1.length - 1 ; i >= 0; i--) {
            long n= (long) Math.pow(10, (ch1.length - 1) - i);
            int x=(ch1[i] - '0');
            long a= x * y;
            sum +=a * n ;
        }
        st.append(sum);
        return st.toString();
    }



    /*public static String solve (String ss, String tt) {
        char[] s=new StringBuilder(ss).reverse().toString().toCharArray();
        char[] t=new StringBuilder(tt).reverse().toString().toCharArray();

        int m=s.length;
        int n=t.length;
        int[] arr=new int[m+n];
        for(int i=0;i<m;i++){
            for(int j=0;j<n;j++){
                arr[i+j]+=(s[i]-'0')*(t[j]-'0');
            }
        }
        int c=0;
        StringBuilder str=new StringBuilder();
        for(int i=0;i<arr.length;i++){
            c+=arr[i];
            str.append((char)(c%10+'0'));
            c/=10;
        }
        while(c!=0){
            str.append((char)(c%10+'0'));
            c/=10;
        }
        // 当×出来结果为零时，会输出多个零
        while (str.length() > 1 && str.charAt(str.length() - 1 ) == '0' ) {
            str.deleteCharAt(str.length() - 1);
        }

        return str.reverse().toString();
    }*/
}
